Sheet separating mechanism



Jan- 7, 1958 L. c. WILLIAMS 2,819,074

SHEET SEPARATING MECHANISM 1 Filed May 1o. 1954 2 sheets-sheet 1 ig: Rl

aan wf J ATToRl/smw Jan- 7, 1958 L. c. WILLIAMS 2,819,074

l SHEET SEPARATING MECHANISM Filed May l0, 1954 2 Sheets-Sheet 2Il"'-I'l-I'IIIIII I az n III MII

'IW ML INVENTOR I LEO C. WILLIAMS FIC7. BY

ATTOR EYS Unite States SHEET SRPARATHNG MECHANISM Application May lit,1954, lSerial No. 428,520

19 Claims. (Cl. 271-26) This invention relates generally to sheetfeeders and more particularly to sheet separating mechanisms of the typewhich are employed in duplicate at opposite sides of the feeder andwhich function to separate and lift the sheets successively at oppositecorner portions thereof from a pile or supply carried on said feeder andstretch said sheets in a direction transverse to the feeding direction.One sheet separating mechanism of the type specified is illustrated anddescribed in the United States Patent No. 2,389,480, granted November20, 1945, to Leonard Baker.

One object of the present invention is to provide for use in a sheetfeeder of the type specified an improved and simplihed mechanism forseparating sheets one from another at a corner portion thereof and formoving the eparated corner portion of each sheet in turn outwardlytransverse to the feeding direction preparatory to forwarding the sheetsto a printing press or other machine to be fed.

Another object of the invention is to provide an improved corner sheetseparating mechanism having a relatively small number of parts novellyconstructed, coordinated and operated to insure efficiency and lowmanufacturing, assembling and maintainance costs.

Another object is to provide a corner sheet separator hav.. improvedoperating mechanism so constructed that certain of the elements servemore than one purpose and perform more than one function in effectingseparation of a corner portion of a sheet and outward transversemovement of said sheet corner portion.

Another object is to provide a corner sheet separator wherein the sheetlifting sucker includes a rigid vacuum conduit movable therewith andguide means associated with said conduit, said conduit and guide meansbeing so constructed and arranged that said sucker is caused to rockinwardly and outwardly with respect to the adjacent side edge of asupply of sheets upon movement thereof toward and away, respectively,from said supply e and lift the topmost sheet therefrom.

A rather object is to provide a sheet separating mechanism havingadjustable means of improved and simplified construction for varying theextent of downward Ymovement of the sheet lifting sucker while thelatter is in operation so as to obtain the best and most accurateseparation of sheets thereby.

The above and further objects and novel features of the presentinvention will more fully appear from the following detailed descriptionwhen the same is read in connection with the accompanying drawings. ltis to be expressly understood, however, that the drawings are for thepurpose of illustration only, and are not intended as a definition ofthe limits of the invention.

in the drawings, wherein like reference characters refer to lil/aeparts, throughout the several views,

Fig. l is a side elevational view, partly in section, illustrating onesheet separating mechanism constructed in accordance with the presentinvention, showing the sheet lifting sticker in the lowered positionwhich it occupies "arent rice when a sheet is about to be gripped andlifted thereby from a supply, certain of the parts having portionsthereof broken away for purposes of clearer illustration;

Fig. 2 is a rear elevational view of said sheet separating mechanism,looking from the right of Fig. l, certain of the parts having portionsthereof broken away for purposes of clearer illustration;

Pig. 3 is a'vertical longitudinal sectional view taken substantially onthe line 3--3 of Fig. 2;

Fig. 4 is a top plan view, partly in section, of said sheet separatingmechanism as viewed from the position indicated by the irregular line 4ld of Fig. l;

Fig. 5 is an enlarged detail top plan View, partly in section, of guidemeans for the sheet lifting sucker;

Fig. 6 is a rear elevational View of the sheet separating mechanism,with parts brolzen away and in section, showing the sheet lifting suckerin the position it occupies after a sheet is gripped and lifted therebyfrom the supply;

Fig. 7 is a fragmentary side elevational view, partly in section,showing a modified form of stop for the sheet lifting sucker, certain ofthe parts having portions thereof broken away for purposes of clearerillustration; and

Fig. 8 is an end elevational view of the modified stop, looking from theright of Fig. 7.

Referring to the drawings, the improved and simplified sheet separatingmechanism, indicated generally at lll, herein shown is located above andadjacent to one rear upper corner of a supply pile of sheets It will beunderstood that in actual practice two of said sheet separatingmechanisms are employed in the sheet feeder, the other being of oppositehand and located above and adjacent to the opposite rear upper corner ofthe pile of sheets il, whereby the topmost sheet is separated and liftedat both rear corner portions from said pile, and through outwardmovement of said corner portions, said sheet is transversely stretchedto straighten and raise the rear edge portion thereof for accuratepresentation to and engagement by sheet forwarding devices, said devicesacting to take the sheet in the region of the stretched portion andimpart to said sheet a forward movement elative to the pile With thisunderstanding that two of the sheet separating mechanisms itl areordinarily employed, and that said mechanisms are identical inconstruction and operation, except that they are of opposite hands, thedescription of the single mechanism herein shown will now proceed.

As herein shown, the sheet separating mechanism lll comprises two spacedparallel side plates il! and f3 which are bolted or otherwise suitablysecured at their upper rear corners to a spacer-block (Figs. 2 3), andadiacent their upper front corners to opposite ends of a spacer-stud ld(Figs. 3 and 4). @ther spacers f6 and bolts 17 located adjacent thelower opposite corners of the side plates l2, i3 serve to further holdsaid plates together in spaced parallel relation. The side plates l2, f3are slidably mounted on two parallel cross shafts ld and l@ to enablelateral adjustment of the entire sheet separating mechanism l@ toaccommodate sheets of different widths. The cross shaft Elli extendsthrough suitable axially aligned clearance openings in the plates liland 13, and the cross shaft lh extends through suitable axially alignedclearance openings in said plates and in the spacer-block ld. The sheetseparating mechanism lll is secured in the desired position ofadjustment thereof along the cross shafts ld, l@ by a jam screw 2idthreaded in the spacer-block ld and engaging the shaft il, The crossshafts i8, l@ are suitably supported at their opposite ends on thefeeder frame to enable longitudinal adjustment of the entire sheetseparating mechanism lil to accommodate sheets of different lengths.

The spacer-block 14 is formed so that a portion 21 thereof (Figs. l, 2and 3) projects outwardly beyond the outer side plate 12, and slidablymounted in said block portion is a vertically disposed open-ended rigidtubular conduit 22. The conduit 22 projects above the spacerblock 14 andhas clamped to the upper end thereof a block 23 provided with a threadedpin 24 which projects downwardly into a suitable clearance openingformed in the portion 21 of said spaced-block. Disposed between theblocks 16 and 23 and threaded on the pin 2d is an adjusting nut 25 bymeans of which the conduit 22 and parts carried thereby to be presentlydescribed may be vertically adjusted with respect to the top of the pileof sheets 11. By virtue of the described arrangement of the adjustingmeans comprising the pin 24 and nut 25, the conduit 22 and parts carriedthereby are free to move upwardly in the event something should engagethe bottom of said parts, and said pin also serves to hold said conduitand said parts against turning movement relative to the spacer-block 14.Upon rotation of the nut 25 in one direction, the conduit 22 is raisedby said nut through engagement thereof with the spacer-block 14, andupon rotation of the nut in the opposite direction, said conduit islowered by gravity assisted by a light spring if deemed necessary ordesirable. Engagement of the nut 25 with the spacer-block 14 holds theconduit 22 and parts carried thereby in adjusted positions and againstdownward sliding movement beyond said positions.

Secured to the lower end of the conduit 22 and comniunicating with saidconduit is an inverted t-shaped tubular tting 26 (Figs. 1, 2 and 4)having a laterally and inwardly directed branch 27 and a forwardlydirected branch 28. Secured in and communicating with the branch 27 ofthe fitting 26 is a rear blow pipe 29. This blow pipe 29 is so shapedand is of such length that the lower end portion thereof is verticallydisposed and extends below the normal feeding level of the top of thepile of sheets 11, and when the sheet separating mecha nism is in itsproper operating position as herein shown, said blow pipe portion ispositioned a desired distance away from the rear face and in from therear corner of the pile. Secured in and communicating with the branch 2Sof the fitting 26 is a side blow pipe 30 which is of the same shape andlength as that of the rear blow pipe 29 so that the lower end portionthereof is likewise vertically disposed and extends below the top of thepile of sheets 11, and is correspondingly spaced from the side face andrear corner of said pile. The blow pipes 29 and 30 are closed at theirlower ends, and each is provided in the vertical portion thereof withair jet means in the form of a relatively thin vertically extending slotor orifice 31 facing the pile of sheets 11.

In the illustrated embodiment, the angularly related blow pipes 29 and30 are located approximately one and one-quarter inches in from the rearcorner of the pile of sheets 11, and approximately onehalf inch awayfrom the rear and side faces, respectively, of said pile. The blow pipes29 and 30 are vertically adjusted by means of the adjusting nut 25 withrespect to the top of the pile of sheets 11 such that the lower ends ofthe air jets issuing from the slots 31 engage a plurality of the topsheets on said pile and the level of the upper ends of said air jets isabove the pile depending upon the extent of sheet separation desired.Air under pressure is delivered to the blow pipes 29 and 3) at therequired predetermined inter* vals through a flexible conduit 32 whichis connected with the upper end of the conduit 22 and with a suitablevalve mechanism (not shown) that is, in turn, connected with an air pump(not shown) or other suitable source of compressed air.

When air under pressure is delivered through the conduits 32 and 22 andfitting 26 to the blow pipes 29 and 30 and issues from said pipesthrough the slots 31 as strong thin elongated jets of air, said jetsimpinge against the rear and side edges of the sheets on the pile 11 andthe tit) air enters under pressure from two angularly related directionsbetween the corner portions of a plurality of the uppermost sheets onsaid pile. The air from the jets so projected intermingles at a pointinwardly from the rear and side edges of the sheets and thus producesbetween the sheets eddying or whirling currents of air which turbinatetoward said sheet edges. Under these conditions, the rear cornerportions of the sheets are caused to raise or fluff-up, as shown inbroken lines in Figs. l, 2 and 3, and become separated one from anotherin a progressive manner beginning with the lowermost sheet and endingwith the uppermost sheet, with the maximum amount of separation beingbetween the top sheet and the next underlying sheet.

When the rear corner portion of the top sheet 33 is preliminarilyseparated by the jets of air as above described, and while said jets ofair continue to act on said sheet, the separated corner portion of thesheet is gripped by a sucker, to be hereinafter described, lifted fromthe pile and moved laterally outward at which time the delivery ofcompressed air to and through the blow pipes 29 and 3l) is discontinued.Since in actual practice two suckers are employed at the opposite rearcorners of the pile of sheets 11 as above explained, it will be apparentthat the top sheet will be stretched transversely of said pile when saidsheet is gripped by the suckers at both separated rear corner portionsthereof and one or both of said corner portions are moved outwardly bysaid suckers. The purpose of this stretching of the sheet is to raiseand straighten the rear edge thereof so that said sheet may beeffectively and accurately presented to and engaged by suitable sheetforwarding devices at said edge.

As herein shown, the sheet lifting and stretching sucker is disposedbetween the side plates 12 and 13 and comprises an open-ended hollow rodor tubular conduit 34 which, as shown in Figs. 2 and 6, is formed toprovide a long upper vertical portion 35, a short lower vertical portion36 which is offset inwardly from said upper portion, and a shortintermediate portion 37 which is inclined downwardly and inwardly fromsaid upper portion to said lower portion. While the conduit 34 mayassume a straight up and down position with respect to the upper surfaceof the pile of sheets 11, it is preferably inclined at a slight angleforwardly from the vertical, as shown in Fig. 3, so that when the topsheet 33 is lifted at the rear thereof from said pile a forward pushingaction will be exerted thereon to maintain the front edge thereof in itsinitial position on said pile.

The conduit 34 has suitably attached to the lower offset portion 36thereof a sheet engaging suction device 33 which is preferably, but notnecessarily, of the type disclosed in the application of Stanley T.Stoothoff and Leo C. Williams, Serial No. 419,378, filed March 29, 1954,needing no detail description herein. Suiice to say that the suctiondevice 38 includes a sheet gripping rubber suction cup 39 which iscarried by and communicates with the conduit 34 and is so formed that itis automatically flexed upwardly a short distance toward and relative tosaid conduit, as shown in Fig. 6, by atmospheric pressure when vacuum iscreated therein and it has gripped and is sealed by the corner portionof the top sheet 13 on the pile 11. This initial movement of the suctioncup 39 compensates for a slight overtravel of the sucker 38 in themovement thereof toward the pile of sheets 11,

whereby gripping engagement of said suction cup with the top sheet 13 isassured without depressing the separated corner portion of said sheetback onto said pile. It will be understood that the well-known cylinderand piston type of suction device, as well as any one of the manywell-known types of suction cups, may be employed and attached to theconduit 34 in lieu of the suction device 3S illustrated herein.

The suction device 3S is guided for straight-line up and down movementby two opposed spool-like rollers 40 and 41 (Figs. 2,` 3, 5 and 6) whichreceive the conduit 34 therebetween and are Iso located that they aredisposed in the path of upward movement of the inclined portion 37 ofsaid conduit. The roller 40 which may be termed the fixed roller, isdisposed outwardly of the conduit 34 and between the furcations of abifurcated bracket 42, and is journalled on a pin 43 which is carried atits opposite ends by said furcations. The bracket 42 is bolted orotherwise suitably secured to the inner surface of the outer side plate12, and said plate is provided with a suitable window 44 therein toafford a clearance space for the roller di?. The roller di, which may betermed the movable roller, is disposed inwardly or at the offset side ofthe conduit 3d and between the horizontal portions of a pair ofangular-shaped links 4S, and is journalled on a pin do carried atopposite ends thereof by said link portions. lThe links 45 projectthrough a suitable clearance window i7 formed in the inner side plate 13and are pivotally mounted exteriorly of said plate at the upper ends ofthe upwardly projecting portions thereof on opposite ends of a pin d8.The pin d8 is carried by a bracket 49 which is disposed between thelinks 45 and is bolted or otherwise suitably secured to the inner sideplate 13. The roller d1 is yieldingly urged toward and into continuousengagement with the conduit 3ft, and said conduit is, in turn,yieldingly urged toward and into continuous engagement with the iixedroller 40 by a pair of coil extension springs 5@ having correspondingends thereof connected to opposite ends of a pin 51 carried by .thelinks d5. The opposite ends of the springs are connected to suitable xedmeans, such as the opposite ends of the pin 43 in the bracket 42.

IBrazed or otherwise suitably secured to the portion 35 of the conduit34 at a point above the rollers 46 and 41 is a block or collar 52 (Figs.2, 3, 4 and 6) having secured therein or formed integrally therewith apin 53 which projects forwardly at right angles to said conduit.Pivotally connected to the pin 53 is the lower end of a verticallyextending link 54 the upper end of which is pivotally connected at 55 to`the rear end of a cam lever S6 which is disposed between the sideplates 12 and 13 and is pivotally mounted at the forward end thereof onthe spacer stud 15. The hub of the lever 56 spans the distance betweenthe side plates 12, 13 so that said lever is held against endwisemovement with respect to said plates. Journalled as at 57 on the lever56 is a cam follower roller S3 which is engaged by a cam 59 that isdisposed between the side plates 12, 13 and is slidably keyed to atransverse cam shaft titl journalled in suitable bearings in said sideplates. The hub of the cam 59 spans the distance between the side plates12, 13 so as to prevent sidewise movement of said cam with respect tosaid plates, and to provide for sidewise adjustment of the cam in unisonwith the plates. The lever 56 is biased by a coil extension spring 61toward the cam 59 to cause the roller 58 to follow said cam, said springhaving one end thereof connected as at 62 to said lever and the oppositeend connected as at 63 to the outer side plate 12. The cam shaft 6@ isdriven in a suitable manner to make one revolution for each cycle ofoperation of the sheet feeder with which the sheet separating mechanismlil is associated.

The cam 59 being fixed to the shaft 60 rotates continuously and thusperiodically raises the lever 56 through engagement of the high part ofsaid cam with the roller 53, and enables lowering of said lever by thespring 61 through engagement of said roller with the low part of saidcam. `It will thus follow that when the lever 56 is lowered, the conduit34 and the suction device 38 carried thereby are, through the describedconnections therefor with said lever, also lowered to substantially theposition thereof shown in Figs. l, l2 and 3 to engage the suction cup 39with the separated corner portion of the top sheet 33, and when saidlever is thereafter raised, said conduit and said suction device arealso raised to the position thereof shown in Fig. 6 to lift said sheetcorner portion gripped by said suction cup to a predetermined position.lin the lowered position of the suction device 38, shown in 2, the upperstraight portion 35 of the conduit 3d is disposed between and engaged bythe rollers and d1, and in the raised position of said suction device,shown in Fig. 6, the inclined portion 37 of said conduit is disposedbetween and engaged by 'said rollers. The upper end of the conduit 34has a iiexible conduit 6dattached thereto which is connected with avacuum pump (not shown) or other suitable source of vacuum throughsuitable valve means (not shown) which controls the making of vacuum inthe suction device 38 through the conduit 3d when said device islowered, and the breaking of vacuum in the suction device after thelatter has been raised and the sheet gripped thereby is transferred toand taken by the sheet forwarding devices hereinbefore referred to.

it is important to note that the described connections for the conduit3d with the lever 56 provide for pivotal movement of said conduit andthe suction device 38 about `the axis of the pin 53 transversely of thepile of sheets 11 and parallel to the rear edge of said pile. It is alsoimportant to note that the inclined portion 37 of the conduit 34constitutes, in effect, a bar-cam. It will thus be apparent that byvirtue of the described pivotal mounting of the conduit 3ft and suctiondevice 3S, and the described shape of said conduit, when the suctiondevice is lowered from the position thereof shown in Fig. 4 to theposition thereof shown in Figs. l, 2 and 3 to engage the separatedcorner portion of the top sheet 33, said suction device and the conduitwill be swung inwardly about the pivot 53 through downward movement ofthe inclined portion 37 of said conduit and engagement of the same withthe fixed roller dd. Such inward movement of the suction device 3hcontinues until the upper straight portion 35 of the conduit 3d passesinto contact with the fixed roller 4G at which time said suction devicewill be disposed in its innermost position, shown in Fig. 2, andsubstantially parallel to the side edge of the pile of sheets 11 forgripping of the separated corner portion of the top sheet 33 by thesuction cup 39. When the separated corner portion of the top sheet 33 isgripped by the suction cup 39 and the suction device 33 and conduit 34are thereafter raised to the positions thereof shown in Fig. 4 to liftsaid sheet, said suction device and conduit will be swung outwardlythrough upward movement of the inclined portion 37 of said conduit andengagement of the same with the fixed roller dll under the influence ofthe spring biased roller dll. Under these conditions, the corner portionof the top sheet 33 gripped by the suction device 33 is moved outwardlyby a yielding action and an extent depending on the slack or sag in saidsheet. When such slack or sag in the sheet is less than the full outwardstroke of the suction device 3S determined by the inclination of theportion 37 of the conduit 3d, the spring biased roller 41 will yieldinwardly upon continued upward movement of said conduit and engagementof said conduit portion with said roller, thus effectively stretchingthe rear edge portion of the sheet without tearing said sheet or causingthe suction cup 39 to `slip thereon.

With the illustrated and described construction, the

retehing of the sheets is accomplished by a yielding action which isparticularly advantageous when handling paper and other similar flexibleand relatively light and thin sheets. in the event it is deemednecessary or desirable to effect the sheet stretching operation by apositive action, as when handling cardboard and other stiff, thick andrelatively heavy sheets, this may be accomplished with the illustratedand described structure by simply re versing the rollers and d1 suchthat the xed roller d@ is disposed at the inner or offset side of' theconduit opposite or outer side of said conduit. Under these conditions,when the conduit 3f; and suction device 38 are,

raised, said conduit and suction device will be forced outwardly againstthe opposition of the spring biased roller di through upward movement ofthe inclined portion 37 of the conduit and engagement of the same withthe fixed roller When the conduit 34 and suction device 38 are lowered,said conduit and suction device will be moved inwardly by the yieldingaction of the spring biased roller il thereon as the inclined portion 37of the conduit travels downwardly relative to the fixed roller fit). Toenable reversal of the rollers 4l@ and dll as above described, andstretching of sheets eectively by a positive action, the outer -sideplate i2 is provided with suitable bolt holes 6:3' for mounting thespring biased roller unit di, 45, do, 48, 49, 51 on said side plate, andthe inner side plate i3 is provided with suitable bolt holes do formounting the xed roller unit fi-ti, d2, d3 thereon.

Simplified stop means are provided for controlling the extent ofdownward movement of the suction device 3S in accordance with the kindof sheet material being handled and the extent of preliminary separationeffected by the ai: jet means on the rear corner portions of theuppermost sheets on the pile ill, so that said suction device will bestopped after the suction cup has contacted the separated corner portionof the top sheet 33 and before said separated corner portion of thesheet is depressed by the suction device back onto the pile. lu thismanner, the corner portieri of the top sheet 33 will be gripped inseparated condition by the suction cup 39, and lifting of said sheetonly and only single sheets from the pile is assured. The extent ofdownward movement of the suction device 38 may be varied while saiddevice is in operation, thus avoiding loss of time and production, andthe simplified stop means for this purpose in the rst form thereof shownparticularly in Figs. 2, 3, 4 and 6, comprises the following elementsconstructed, mounted and adjusted as follows.

Disposed betr ee and in close proximity to the side plates 12 and i3 andlocated between the block 52 on the conduit 3ft and the guide rollers d@and di are two arms 67 which are pivotally mounted at the front endsthereof on a pin 65 carried by said side plates. The arms 67 receive theconduit 3d therebetween and they extend rearwardly beyond the rear edgesof the side plates 12, 13. Disposed between and carried, as at o9, bythe arms 67 is an abutment-block 70 which is located in the path ofdownward movement of the block 52 on the conduit 34. The abutment-block7d projects above the arms 67 for engagement by the block S2, and isformed of a suitable shock and noise absorbing material, such as nylon.The arms 67 carry at the rear ends thereof a pin 7l to which ispivotally connected a threaded rod '72 which extends upwardly through asuitable clearance opening in the spacerblock 141 and has an adjustingnut 73 threaded on the upper end thereof above said block. The abutmentor bumper-block 7@ also serves to hold the arms 67 in spaced relation,and spacer-collars 74 are engaged over the pin 7i and located atopposite sides of the rod 72 to hold the latter against sidcwisemovement. The adjusting nut 73 is held against accidental rotation by aleaf-spring detent 75 which is secured to the spacer-block 14 andengages the lower knurled portion of the hub of said nut. The suctiondevice 33 is shown in Fig. 3 in its lowered position with the block 52engaged with the abutment-block 70, thus preventing the cam followerroller 5t; from following the full drop of the cam 59 and holding thesuction device against further downward movement beyond said position.It will thus be apparent t. upon rotation of the adjusting nut "/'3 inopposite directions, the arms 67 and abutment-block iti thereon will beraised and lowered about the pivot 6ft relative to the conduit 3d and,hence, the suction device 33 may be stopped in any desired downwardposition through relative adjustment of the abutment-block '70 by theadjusting nut 73 and engagement thereof by the block 52 on the conduit3d.

ln the second form of stop means shown in Figs. 7 and 8 for the suctiondevice 3S, the previously described rod 72, adjusting nut 73,spacer-collars 74 and detent 75 are eliminated, and longer arms 76 areemployed in lieu of the previously described arms 67 and pivotallymounted on the pin d8 to carry the abutment-block 70 at 69 thereon.Disposed rearwardly of the abutment-block 70 and extending between thearms 76 is an arcuate-shaped rack 77 which is provided in the rearsurface thereof with a plurality of upwardly facing ratchet-like teeth78. The rack 7'7 is concentrically disposed with respect to the pivot edof the arms 7d and is bolted or otherwise suitably secured to the sideplates l2 and 13, spacer-collars 79 being provided on opposite sides ofsaid raclt to locate the same centrally between said side plates andsaid arms and to hold said rack against sidewise movement. Disposedbetween the rear end portions of the arms 76 is a ting-pressedlatch-bloei; d@ provided at the front end thereof with a tooth hl whichis adapted to engage the teeth 7d of the rack 77. The latch-block 8d isslidably mounted on two pins S2 which are carried by the arms 76 andextend through elongated clearance openings 83 in said block. The springfor the latch-block Si? is indicated at 84 .and is of the coilcompression type and is disposed within a socket S5 formed in saidblock, one end of said Vspring engaging against the bottom wall of saidsocket and the opposite end engaging against the rearrnost pin $2,whereby the latch-block is continuously urged toward and into engagementwith the teeth 78 of the rack 77. The tooth dl of the latch-block 0 maybe engaged selectively with any tooth 7d of the rack 77 throughretraction of said block and swinging movement of the same and the arms76 about the pivot 68. Such swinging movement of the arms 7e impartscorresponding movement to the abutment-block 79, thus positioning saidblock for engagement by the block 52 when the suction device 38 reachesthe desired position in 'the downward movement thereof. Theabutment-block 7) is then locked in position through release of thelatch-block 80 and action 0f the spring S4 which causes the tooth 3l onsaid latchblocl: to engage the adjacent tooth of the rack 77. Thelatch-block Sil may be disengaged from the rack 77 and theabutment-block 70 may be adjusted as and for the purpose above describedwhile the suction device 38 is in operation.

The operation of the sheet separating mechanism embodying the presentinvention will be clearly understood from the foregoing description, andwhile said description and the accompanying drawings set forth with moreor less particularity one embodiment of the invention, it is to beexpressly understood that said invention is not limited to saidembodiment. Various changes may be made in the mechanical details, someof which have been suggested in the foregoing specification, and in thedesign and arrangement of the parts illustrated without departing fromthe spirit and scope of the invention, as will now be apparent to thoseskilled in the art. For a definition of the limits of the invention,reference is had primarily to the appended claims.

What is claimed is:

l. In a sheet separato-r for separating sheets one at a time from thetop of a supply thereof, a hollow upwardly extending elongated elementhaving a cam surface thereon facing a side edge of said supply, a sheetgripping sucker pneumatically and mechanically connected to saidelement, an operating member for said sucker connected with saidelement,the connection between said element and said member being a pivotpermitting swinging movement `0f said element and said sucker inopposite directions laterally of said supply, means for operating saidmember to move said element and said sucker vertically toward and awayfrom said supply, a xed follower arranged for engagement by said camsurface, said cam surface acting to swing said element and said suckerin one of said lateral directions upon vertical movement of said elementand said sucker in one direction, and yieldable means acting to swingsaid clement andy said sucker in the other of said lateral directionsupon vertical movement of said element and said sucker in the oppositedirection.

2. In a mechanism of the class described, a hollow upwardly extendingelongated element arranged above a supply of sheets and having a camsurface thereon facing a side edge of said supply, a sheet grippingsucker pneumatically and mechanically connected to said element, anoperating member for said sucker connected with said element, theconnection between said element and said member being a pivot permittingswinging movement ot said element and said suclter inwardly andoutwardly laterally of said supply, means for operating said member tomove said element and said sticker toward and away from said supply, alixed follower ananged for engagement by said cam surface, said camsurface being formed so as to impart said inward lateral movement tosaid element and said sticker upon movement `of the latter and saidelement toward said supply, and biasing means continuously applying ayieldable force upon said element in the direction of said follower soas to impart said outward lateral movement to said element and saidsucker upon movement of the latter and said element away from saidsupply.

3. ln a sheet separator for separating sheets one at a time from the tcpof a supply thereof, an upwardly extending rod having a cam surfacethereon facing a side edge of said supply, a sheet gripping suckercarried by said rod, an operating member for said sucker connected withsaid rod, means for operating said member to move said rod and saidsticker toward and away from said supply, the connection between saidrod and said member being a pivot permitting swinging movement of saidrod and said sticker inwardly and. outwardly laterally of said supplyduring movement of the same toward and away, respectively, from saidsupply, a fixed roller arranged for sliding engagement by said camsurface to swing said rod and said sucker about said pivot in onedirection, a movable roller arranged opposite said fixed roller, and aspring acting upon said movable roller and at all times urging the sametoward said fixed roller to thus engage said rod and swing the same andsaid sucker about said pivot in the opposite direction.

4. Apparatus as delined in claim 3 wherein said rod is hollow andcommunicates with said sucker, and said rollers are hanged to connuesaid rod.

5. Apparatus as .defined in claim 3 wherein said rod is shaped toprovide an upper vertical portion, a lower vertical portion offsetlaterally from said upper portion, and an intermediate portionconnecting said upper and lower portions and inclined downwardly fromsaid upper portion to said lower portion, said inclined intermediateportion providing said cam surface on said.rod.

6. ln a sheet separator for separating sheets one at a time from the topof a supply thereof, a rigid tubular conduit shaped to provide an uppervertical portion, a lower ertical portion offset from said upper portiontoward a edge of said supply, and an intermediate portion connectingsaid upper and lower portions and inclined downwardly from said upperportion to said lower portion, a sheet gripping sucker carried by saidlower conduit portion and communicating with said conduit, a levermounted for pivotal movement about a horizontal transverse axis, a linkmounted on said lever for pivotal movement about a horizontal transverseaxis and connected with said upper conduit portion, the connectionbetween said link and said conduit being a pivot permitting swingingmovement ot said conduit and said sucker inwardly and outwardlylaterally of said supply, a pair of flanged rollers positioned atopposite sides of said conduit and in the path traversed by saidinclined portion of the conduit, means mounting one of said rollers infixed position, means mounting the other of said Irollers for movementtoward and away lfrom the ixed roller, a spring operatively connectedwith said movable roller to continuously urge the same toward said xedroller and means for swinging said lever to raise and lower said conduitandsaid sucker, said rollers cooperating to guide said conduit forstraight-line upward and downward movements, and said rollers and saidinclined portion of the conduit cooperating to effect said inward andoutward movements of said conduit and said sucker upon downward andupward movements, respectively, of said conduit and said sucker.

7. Apparatus as defined in claim 6 wherein the inward lateral movementof the conduit and sucker is effected by the iixed roller, and theoutward lateral movement is ciected by the movable spring-biased roller.

8. Apparatus as defined in claim 6, comprising means on said conduitproviding a downwardly facing shoulder, an abutment arranged forengagement by said shoulder to limit the downward movement of saidconduit and the sucker, and means connected with said abutment andmovable to different positions 'to adjust said abutment to variousoperative positions and thereby vary the extent of downward movement ofsaid conduit and said sucker.

9. Apparatus as deiined in claim 8 wherein said abutment adjusting meanscomprises an arm mounted for pivotal up and down movement about a fixedhorizontal axis and having the abutment attached thereto, a verticallyextending threaded rod pivotally connected with said arm, a iixed guidefor said threaded rod, and an adjusting nut on said threaded rod andengaging said guide, said adjusting nut upon rotation thereof effectingpivotal movement of said arm and said abutment.

l0. Apparatus as delined in claim wherein said abutment adjusting meanscomprises an arm mounted for pivotal up and down movement about a lixedhorizontal axis to diierent positions and having the abutment attachedthereto, a latch element carried by said arm, and a fixed rack havingteeth with which said latch element may be selectively engaged forreleasably holding said arm in any of said positions.

ll. Apparatus as defined in claim l0 wherein said latch element isslidably mounted on said arm for movement into and out of engagementwith said rack, and comprising a spring for releasably holding saidlatch element engaged with the selected teeth of said rack.

l2. In a sheet separator, an upwardly extending rod, a sheet grippingsucker carried by said rod, means for lowering and raising said rod tomove said sucker into and out of engagement with the top of a supply ofsheets, and means for limiting the downward movement of said sucker andfor stopping the latter in a desired operating position with respect tothe top of said supply comprising, an abutment on said rod, an armmounted for pivotal up and down movement about a lixed horizontal axisto various positions, and an abutment attached to and movable with saidarm to said positions and arranged for engagement by the abutment onsaid rod.

i3. ln a sheet separator, a sheet gripping sucker, means for loweringand raising said sucker into and out of engagement with the top of asupply of sheets, pivoted stop means for limiting the downward movementof said sucker and movable to dilerent operative positions to therebystop said sucker in dierent operating positions with respect to the topof said supply, and latch means for releasably holding said stop meansin any of its said positions.

14. In a sheet separator, a sheet gripping sucker, means for loweringand raising said sucker into and out of engagement with the top of asupply of sheets, and means for limiting the downward movement of saidsuelter and for stopping the latter in a desired operating position withrespect to the top of said supply and comprising, an abutment movablewith said suclter, an arm mounted for pivotal up and down movement abouta lixed horizontal axis to dierent positions, an abutment attached toand movable with said arm to said positions and arranged for engagementby said first-named abut- 11 ment, a latch element, a rack elementhaving teeth with which `said latch element may be selectively engaged,means for mounting one of said elements in fixed position, and means formounting the other of said elements on said arm, said elementscooperating to releasably hold said arm in any of its said positions.

15. Apparatus as defined in claim 14 wherein the rack element is fixed,and the latch element is mounted on the arm for sliding movement intoand out of engagement with said rack, and comprising a spring forreleasably holding said latch element engaged with the selected teeth ofsaid rack.

16. A sheet separating mechanism arranged for operation on a cornerportion of the top sheet of a supply of sheets, comprising two sideplates, spacer means including a stub-shaft rigidly connecting said sideplates in spaced parallel relation, a tubular conduit disposed betweensaid side plates and shaped to provide an upper vertical portion, alower vertical portion laterally offset inwardly from said upperportion, and an intermediate portion inclined downwardly from said upperportion to said lower portion, a sheet gripping sucker carried by saidlower conduit portion and communicating with said conduit, a leverpivotally mounted on said stub-shaft, a link connected with said leverfor pivotal movement about an axis parallel to the axis of saidstub-shaft, a block secured to said upper conduit portion and connectedwith said link, the connection between said block and said link being apivot permitting swinging movement of said conduit and said suckerinwardly and outwardly laterally of said supply, a pair of hangedrollers positioned in opposed relation at opposite sides of said conduitand in the path traversed by said inclined portion of the conduit, meansmounting one of said rollers on one of said side plates in fixedposition, means mounting the other of said rollers on the other of saidside plates for pivotal movement toward and away from the fixed roller,a spring operatively connected with the movable roller to continuouslyurge the same toward the fixed roller, a driven cam shaft along whichsaid side plates are movable, a cam disposed between said plates andslidably keyed to said cam shaft, said cam acting to positively liftsaid lever and thereby raise said conduit ISO and said sucker, andyieldable means operatively connected to said lever and to one of saidside plates to cause said lever to follow said cam and thereby lowersaid conduit and said sucker, said rollers cooperating to guide saidconduit for straight-line upward and downward movements, and saidrollers and said inclined portion of said conduit cooperating to effectsaid inward and outward lateral movements of said conduit and saidsucker upon downward and upward movements, respectively, thereof.

17. Apparatus as defined in claim 16 wherein the movable roller isdisposed at the offset side of said conduit, whereby the conduit and thesucker upon upward movement thereof are caused to swing outwardly by theyielding action of said roller.

18. Apparatus as defined in claim 16 comprising a pair of arms disposedbetween the side plates and at opposite sides of the upper portion ofthe conduit, means mounting said arms at corresponding ends thereof onthe side plates for pivotal up and down adjustment below the block onsaid conduit, and an abutment member attached to said arms andpositioned for engagement by said block to thereby limit the downwardmovement of said conduit and consequently the sucker.

19. Apparatus as defined in claim 18, comprising a latch elementslidably mounted on said arms and disposed between the latter at theopposite ends thereof, an

renate-shaped rack extending between said arms and secured to said sideplates in concentric relation with the pivotal mounting for said arms,said rack having teeth with which said latch element may be selectivelyengaged for holding said arms in any position of adjust ment thereof,and a spring for releasably holding said latch element engaged with theselected teeth of said rack.

References Cited in the file of this patent UNITED STATES PATENTS2,108,702 Backhouse Feb. 15, 1938 2,222,459 Backhouse Nov. 19, 19402,389,480 Baker Nov. 20, 1945 2,402,442 Perry .Tune 1.8, 1946 2,434,530Williams Jan. 13, 1948

